Pressure relieving closure cap

ABSTRACT

A cap for closing a container comprises a housing defining an enclosed space, and a circular plate connected to the housing and subdividing the enclosed space into two chambers, one of which communicates with the exterior of the housing and the other of which communicates with the interior of the container. The circular plate is formed in its central region with an annular elevated portion facing the other chamber and surrounding a circular depression. At least one aperture is provided in the plate radially outwardly of the elevated portion and establishing communication between the two chambers. An elastically yieldable diaphragm is connected to the circular plate in its outer marginal portion, and is provided with a central hole bounded by an inner marginal portion which is normally urged by pretension in the diaphragm into contact with the elevated portion. At least one groove is provided in the elevated portion establishing communication between the aperture and the central opening and, consequently, between the two chambers in such a manner that gaseous fluid is permitted to pass between the two chambers through the groove at a first volumetric rate at all times, and at a higher second volumetric rate when the pressure in the one chamber exceeds that in the other chamber to a degree sufficient to deflect the inner marginal portion of the diaphragm out of contact with the elevated portion of the central plate, while liquid is prevented from leaving the interior of the container.

United States Patent 1191 Gerdes 1 Jan. 7, 1975 I PRESSURE RELIEVINGCLOSURE CAP [57] ABSTRACT inveniofl Gerdes Lflngenfeid, Germany A capfor closing a container comprises a housing de- [73] Assigneez m KGFabrik Fuer v fining an enclosed space, and a circular plate con-Kraftfahrzeugteile, Langenfeld, nected to the housing and subdividingthe enclosed Germany space mto two chambers. one of which communicateswith the exterior of the housing and the other of which Flledi 1972communicates with the interior of the container. The

[21] APPL N0: 303,216 circular plate is formed in its central regionwith an annular elevated portion facing the other chamber andsurrounding a circular depression. At least one aperl Cl -220/205137/5135, 220/200 ture is provided in the plate radially outwardly ofthe 229 elevated portion and establishing communication be- [51] llnt.Cl. 865d 51/16, Fl6k 17/00 tween the two Chambers. An elasticallyyieldable i Field of Search 220/44 R, 24 GT; 137/493, phragm isconnected to the circular plate in its outer 137/218, 513-5 marginalportion, and is provided with a central hole bounded by an innermarginal portion which is notl l References Cited mally urged bypretension in the diaphragm into UNITED STATES PATENTS contact with theelevated portion. At least one groove 3,047,235 7/1962 Eshbaugh et al220/44 R is Provided in the elevated Portion establishing 3,194,2627/1965 Hamilton et a1. 137/5135 munication between the aperture and theCentral 3,333,836 8/1967 Bahout 137/5135 opening and, consequently,between the two chambers 3,580,273 5/l971 Schwarz 137/ in such a mannerthat gaseous fluid is permitted to Miller R pass between the twochambers through the groove at FOREIGN PATENTS 0 APPLICATIONS a firstvolumetric rate at all times, and at a higher second volumetric ratewhen the pressure in the one chamber exceeds that in the other chamberto a de- 1,145,304 10/1957 France 220/44 R gree sufficient to deflectthe inner marginal portion of 904,367 7 49 Germany 137 493 the diaphragmout-of contact with the elevated por- OTHER PUBLICATIONS PrimaryExaminer-William 1. Price Assistant Examiner-Allan N. Shoap Attorney,Agent, or Firm-Michael S. Striker tion of the central plate, whileliquid is prevented from leaving the interior of the container.

7 Claims, 3 Drawing Figures PRESSURE RELIEVING CLOSURE CAP BACKGROUND OFTHE INVENTION The present invention relates to a cap for closingcontainers, such as storage receptacles or pipes.

There are already known various caps for closing containers in which aflexible diaphragm abuts against one or more rigid profiled members soas to selectively close or open at least one pressure equalizing passageor aperture in such a manner that liquid is prevented from escaping fromthe container while the gas pressure inside the container is equalizedwith that of the ambient atmosphere.

It is already known, particularly in connection with caps for closingfuel tanks of motor vehicles, to obtain pressure equalization betweenthe interior and exterior of the container by means of a diaphragmhaving a central hole and contacting an elevated portion of a rigidprofiled member located inside the cap, the elevated portion beingprovided with a channelextending diametrically of the elevated portionand communicating with the central hole of the diaphragm, so that gas ispermitted to pass through the central hole in the diaphragm while liquideven in droplet form is prevented from passing therethrough. Thedimensions of the channel are so selected that only vapor or air canpass therethrough while liquid droplets adhere to the surfaces boundingthe channel and are prevented from passing through the channel.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide a cap for closing a container which is more effective than theheretofore known caps.

It is a further object of the present invention to provide a cap forclosing a container which insures fast and reliable response to thechange of the pressure conditions prevailing inside the container.

In pursuance of these objects and of others which will become apparenthereafter, one feature of the present invention resides, in a cap forclosing a container, in an arrangement for controlling the passage of agaseous fluid between the exterior and the interior of the container,which means includes a diaphragm clamped within the cap in the region ofits circumferential marginal portion and urged by pretension intocontact with an elevated portion of a rigid circular member connected tothe cap interiorly thereof. A rigid insert is provided with throughapertures located outwardly of the elevated portion of the circularmember and with pressure-equalizing grooves. The elevated portion is ofannular configuration, and the grooves are formed therein and extendradially thereof, establishing communication between the two sides ofthe annular elevated portion. The control diaphragm, which abuts againstthis annular elevated portion, is provided with a circular central holebounded by an inner marginal portion which projects radially inwardlyfor the annular elevated portion. The interior of the containercommunicates with the exterior thereof via the central hole in thediaphragm, the radially extending grooves in the annular portion, theapertures in the rigid insert wall and the lower edge of the cap.

The invention will now be described with reference to the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional side view of abayonet-type closure cap according to the invention;

FIG. 1a is a bottom-plan view of an elevated annular portion of therigid insert member; and

FIG. 2 is a sectional side view of a modified embodiment of theinvention provided with a mortise lock.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing the drawings indetail, and first the embodiment shown in FIGS. 1 and la, it may be seenthat the housing of the cap is comprised of an upper housing portion 1which is formed with a grip portion I extending upwardly of the uppercap portion l and diametrically thereof and with a cap edge portion 1"extending downwardly from the upper housing portion 1 and constituting acircumferential wall, and of a lower housing portion 2 of cup-shapedconfiguration having a flange edge portion 2 extending toward the capedge portion 1". A rigid insert 3 is clamped in the region of itsmarginal portion to the upper housing portion 1 and is provided with anannular elevated portion 3' in its central region which faces towardslower housing portion 2. The rigid insert 3 subdivides the space boundedby the upper housing portion 1 and the lower housing portion 2 in anupper chamber la and a lower chamber 2a. The rigid insert 3 is providedwith a plurality of apertures 3 located radially outwardly of theannular elevated portion 3' and establishing communication between thechambers la and 2a. A plurality of grooves 3 which are also illustratedin FIG. la is provided in the annular elevated portion 3, extendingradially thereof and establishing communication between a depressionsurrounded by the annular elevated portion 3' and the apertures 3", aswill be explained in more detail later on. In the lower chamber 20,there is provided an annular sealing element 5 and a control diaphragm 4clamped in the region of its outer marginal portion between the sealingelement 5 and the insert 3. The diaphragm 4 is provided in its centralregion with a circular hole bounded by an inner marginal portion whichis urged by pretension in the control diaphragm 4 into contact with theannular elevated portion 3 and projects radially inwardly beyond thesame. The grooves 3" are distributed over the circumference of theannular elevated portion 3' extending radially thereof and establishcommunication between the chamber 2a and the chamber la via the centralhole 4 and the apertures 3".

The cap is provided with a conventional springloaded bayonet-typeconnector which is known in the art and is not described. When the capis connected with the container, by means of the connector, the lowerchamber 2a communicates with the interior of the container. The capoperates for equalizing the pressure between the interior and exteriorof the container in the following manner:

When the pressure inside the container is the same as that outside thecontainer, the control diaphragm 4 is urged by the pretension thereininto contact with the annular elevated portion 3' of the rigid insert 3;when the pressure inside the container and thus in the lower chamber 2adrops below the pressure outside the container and thus in the upperchamber la, the pressure drop across the diaphragm 4 displaces the innermarginal portion thereof downwardly and out of contact with the annularelevated portion 3' so that air from the outside of the container canenter the upper chamber la through the passages 6 and cutouts 7 ofconventional design, and proceeds through the apertures 3", between theannular elevated portion 3' and the inner marginal portion of thediaphragm 4 and through the central hole 4 into the lower chamber 2a andfrom there into the interior of the container.

On the other hand, when the pressure inside the container exceeds thatoutside thereof, the pressure drop across the diaphragm 4 is added tothe pretension therein, thus pressing the inner marginal portion thereofagainst the annular elevated portion 3', ln this manner, the onlycommunication between the upper chamber 19 and the lower chamber 2a isestablished via the radially extending grooves 3" provided in theannular elevated portion 3' so that the air at elevated pressure ispermitted. to pass from the interior of the container to the exteriorthereof via the chamber 2a, the central hole 4, the grooves 3", theapertures 3", the cutouts 7 and the passages 6. It is to be mentioned inthis connection that the cutouts 7 may either be provided directly inthe rigid insert 3, or a separate spacing ring may be provided betweenthe rigid insert 3 and the upper cap portion 1, and the cutouts 7 may beprovided therein.

A modified embodiment of the invention is illustrated in FIG. 2, inwhich the cap is provided with a mortise lock serving for locking thecap and thus preventing unauthorized opening of the container. In thisembodiment, a rigid insert 9 is substituted for the rigid insert 3 ofthe previously-described embodiment of the invention, and is providedwith a central opening through which the lock extends into a lowerhousing portion 12. The rigid insert 9 is provided with an innermarginal portion 9' surrounding the central opening, and a sealing ring8 is interposed between the inner marginal portion 9' and the lock 10.The construction and operation of the mortise lock 10 is entirelyconventional and thus will not be discussed.

The rigid insert 9 is provided with an annular elevated portion 3' whichis formed with grooves 3" similar to those described in connection withthe first embodiment of the invention. The operation of the cap issimilar to that previously described. Accordingly, when the pressureinside the container exceeds that outside thereof, excess air can escapefrom the interior of the container through the central opening 4' of thecontrol diaphragm 4, through the grooves 3" provided in the elevatedannular portion 3', through the holes 3" provided in the rigid insert 9,to the outside of the cap and of the container through the cutouts 7 andthe passages 6. On the other hand, when the pressure inside thecontainer drops below the pressure outside the same, the diaphragm 4which is pressed against the annular elevated portion 3' by pretensiontherein is displaced downwardly out of contact with the annular elevatedportion 3' so that outside air can pass through the passages 6, thecutouts 7, the apertures 3", through the gap between the annularelevated portion 3' and the inner marginal portion of the diaphragm 4,and through the control hole 4' to the interior of the container.

The pressure equalizing grooves 3" which extend radially of the annularelevated portion 3' and which are distributed over the circumferencethereof, can either be notches machined in the annular elevated portionor depressions pressed into the same. The aper tures 3" which extendthrough the rigid insert 3 or 9 radially outwardly of the annularelevated portion 3' may preferably be located diametrically opposite oneanother and the combined cross-sections of the apertures may be soselected as to afford the required flow rate therethrough.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims.

1. In a cap for closing a container. a combination comprising first wallmeans defining an enclosed space; second wall means connected to saidfirst wall means and subdividing said space into a first and asecondchamber and including a circular plate formed with an annularelevated portion in the central region thereof facing said secondchamber and surrounding a circular depression; means for establishingcommunication between said first chamber and the exterior of said firstwall means; means for establishing communication between said secondchamber and the interior of the container; means for establishingcommunication between said first and second chambers and including atleast one aperture in said second wall means radially outwardly of saidelevated portion; and means situated in said second chamber andoperative for controlling the passage of a gaseous fluid through saidaperture and including an elastically yieldable diaphragm having anouter marginal portion fluid-tightly connected with said circular plateand an inner marginal portion bounding a central hole in said diaphragmcommunicating with said depression, and normally urged by pretension insaid diaphragm into contact with said elevated portion, and at least onegroove extending in said elevated portion radially outwardly thereof forestablishing comm unication between said depression and said aperture,whereby the gaseous fluid is permitted to pass at least from said secondchamber into said first chamber at a first volumetric rate when thepressure in the former exceeds that in the latter, and from said firstchamber into said second chamber at a second higher volumetric rate whenthe pressure in the former exceeds that in the latter to such a degreethat said inner marginal portion of said diaphragm is deflected out ofcontact with said elevated portion of said circular plate.

2. A cap as defined in claim 1, and further comprising a plurality ofadditional grooves similar to said groove and distributed along thecircumference of said annular elevated portion extending radiallythereof.

3. A cap as defined in claim 2, wherein said grooves are notches cutinto said annular elevated portion.

4. A cap as defined in claim 2, wherein said grooves are depressionspressed into said annular elevated portion.

5. A cap as defined in claim 2, wherein said grooves are undulated andextend at least partially circumferentially in said annular elevatedportion.

6. A cap as defined in claim 1, and further comprising a plurality ofadditional apertures similar to said aperture and situated along acircle outwardly surrounding said annular elevated portion.

7. A cap as defined in claim 6, wherein said apertures are arranged inpairs diametrically opposite one another across said annular elevatedportion.

UNITED STATES'PATENT OFFICE CERTIFICATE OF CORRECTION.

PATENT NO. Q 3- 53 75 DATED January 7, 1975 mvmrorus) GERDES It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

In the heading insert (30) Foreign application priority date November lO,l97l,Germany P 21 55 854.3

Signed and sealed this 20th day of May 1975.. v

(SEAL) Attest: I

, I C. MARSHALL DANN RUTH C. MASON Commissioner of Patents AttestingOfficer and Trademarks

1. In a cap for closing a container, a combination comprising first wallmeans defining an enclosed space; second wall means connected to saidfirst wall means and subdividing said space into a first and a secondchamber and including a circular plate formed with an annular elevatedportion in the central region thereof facing said second chamber andsurrounding a circular depression; means for establishing communicationbetween said first chamber and the exterior of said first wall means;means for establishing communication between said second chamber and theinterior of the container; means for establishing communication betweensaid first and second chambers and including at least one aperture insaid second wall means radially outwardly of said elevated portion; andmeans situated in said second chamber and operative for controlling thepassage of a gaseous fluid through said aperture and including anelastically yieldable diaphragm having an outer marginal portionfluid-tightly connected with said circular plate and an inner marginalportion bounding a central hole in said diaphragm communicating withsaid depression, and normally urged by pretension in said diaphragm intocontact with said elevated portion, and at least one groove extending insaid elevated portion radially outwardly thereof for establishingcommunication between said depression and said aperture, whereby thegaseous fluid is permitted to pass at least from said second chamberinto said first chamber at a first volumetric rate when the pressure inthe former exceeds that in the latter, and from said first chamber intosaid second chamber at a second higher volumetric rate when the pressurein the former exceeds that in the latter to such a degree that saidinner marginal portion of said diaphragm is deflected out of contactwith said elevated portion of said circular plate.
 2. A cap as definedin claim 1, and further comprising a plurality of additional groovessimilar to said groove and distributed along the circumference of saidannular elevated portion extending radially thereof.
 3. A cap as definedin claim 2, wherein said grooves are notches cut into said annularelevated portion.
 4. A cap as defined in claim 2, wherein said groovesare depressions pressed into said annular elevated portion.
 5. A cap asdefined in claim 2, wherein said grooves are undulated and extend atleast partially circumferentially in said annular elevated portion.
 6. Acap as defined in claim 1, and further comprising a plurality ofadditional apertures similar to said aperture and situated along acircle outwardly surrounding said annular elevated portion.
 7. A cap asdefined in claim 6, wherein said apertures are arranged in pairsdiametrically opposite one another across said annular elevated portion.